Fine texture casting



May 19, 1942- v s. R. M BRIDE FINE TEXTURE CASTING Filed Feb 6, 1940INVENTOR.

I 1 SAMUEL ROSS McBRIDE BY 0%,KW? 0x4 ATTORNEYs Patented May 19, 1942EEQE FINE TEXTURE CASTING Application February 6, 1940, Serial No.317,573

11 Claims.

This invention relates to casting, and more particularly casting ofmetals which are prone to offer difiiculty from tendencies to unevengrain formation in the product; and it is among the objects of theinvention to provide procedure and means for handling and setting themolten metal to form products with highly desirable and uniform grainstructure and with clear finish.

To the accomplishment ofthe foregoing and related ends, the invention,then, comprises the features hereinafter fully described, andparticularly pointed out in the claims, the following description andthe annexed drawing setting forth in detail certain illustrativeembodiments of the invention, these being indicative however, i

of but a few of the various ways in which the principle of the inventionmay be employed.

In said annexed drawing- Fig. l is a vertical sectional view of-a moldin accordance with the invention; Fig. 2 is a transverse section takenon a plane substantially indicated by line IIII, Fig. 1; Figs. 3 and 5are side elevational views of modifications ;'and Fig. 4 is a transversesection taken on a plane substantially indicated by line IV-IV, Fig. 3.

Referring more particularly to the drawing,

there is shown in Figs. 1 and 2 a mold, in vertically divided sections2, 2, which mate together and are held by convenient means, such as arecessed foundation of corresponding size, or by clamps etc., as may bedesired. Within is a mold-filling well 5, and one or more mold cavities6 as desired. The inlet 1 to the filling well vmay be flared tofacilitate use with a metal charger. Proceeding from the filling well 5to the mold cavities are a plurality of vertically spaced openings 9,Ill, etc. And, these expand outwardly and also downwardly to the moldcavities. With the arrangement of a mold-filling well and plurality ofvertically spaced openings therefrom to the moldcavities, it becomespossible to simultaneously cast articles of dissimilar crosssection suchas could not otherwise be practiced on account of the metal of one sizetending to freeze up prematurely before that of the other. The materialof the mold sections may be of permanent character, as for instance castiron, for the casting of certain alloys, or it may be of baked sand orof like character, for relatively high temperature usage, being backedby shell backing 3. At the bottom of the central passageway 5 is asettling cavity I l to collect foreign particles which otherwise mightbe swept into the mold cavities with rush of the pouring metal. Byhaving a metal bottom piece [5, even where the mold surface is of sand,abrasion of the surface upon which the metal falls isavoided.

The bottom of the mold cavities is formed preferably of metal blocks I6,and where cores are desired these may have core-holding recesses llwhereby a core [3 may be positioned. .A recessed metal block 20 maycorrespondingly form the topof the mold cavity, and a recess 2| thereinsimilarly may position the upper end of the core. The material of thecores may be metal, as for instance steel, or sandcores may be employed.Where desired, the cores may have a slight taper. By the use of therecessed metal blocks for the core positioning, cores of different sizescan be put into the assembly, at will. By providing the top mold blockwith a rebate 22 whereby the block may fit into the mold cavity as faras the shoulder, particular accuracy of positioning and durability isassured. The top block further may have a projecting ledge 25 tofacilitate lifting off by suitable tongs or other instrument.

In the process of casting, the molten metal is poured in through theinlet 1, and fillsthe set tling chamber l4 and thence overflows throughthereby preventing detrimental jet-eifects into the mold. .Aparticularly efficient distribution is rapidly attained withoutexcessive turbulence. Rapidly welling on up into the mold cavities,metal overflow next takes place through. the openings iii, and then insuccession the openings .9; and so on, the number of these in any casedepending upon the size and height of the casting.

'As a furtherrefinement, I provide a particular relationship between thedimensions of the opening and the section of the mold cavity. That is,the inlet l3, etc., of the opening .to the mold cavity is of verticaldimension between one-third and one-fourth the diameter of the moldcavity, 5

and the vertical dimension of the opening is also approximately one-halfthe vertical dimension of the mold wall intervening'between openings. As

a result of .7 the relationship established, it is separated and thecores removed, and on re-assembling, the mold is ready for the nextpour.

When very long cores are involved, additional core-adjusting means maybe provided, and this may be in the form for instance of a guide 21,Fig. 3, as a ring or partial ring, adjusted by a screw-threaded stem 28extending therefrom through a bracket 29 attached to the mold shell, andhaving adjusting nuts 30. The lower end of the core may be centered bythe end block 3|.

Gas vent ways are desirably provided between the mold shell sections andthe sand liner, such as ducts 33, Fig. 4, within the shell sections 2a,2a.

By means of hinges, the mold sections shown in all of the figures may beconnected together so as to match accurately and conveniently, and thushinge members 35 may be secured to the opposed shell sections. Forlocking the sections at the other side, lugs 31 may be carried by thesections and have a screw-threaded take-up means coacting therewith, andwhich, for instance, may be a screw-threaded stem 38 extending from onelug through an opening in the other and into a screw-threaded barrel 39having a turning handle 40.

As a preferred arrangement where casting certain alloys, the core l8a,Fig. 5, is connected to a fluid-operated plunger 42 so as to bewithdrawable thereby, the core fitting through the metal bottom block43, and in casting, when the metal is formed and solidifies sufficientlyto stand against collapse, the cast metal is held by the bottom piece 43while the core is drawn slidingly along the setting metal. This, I find,gives a peculiar skin-effect finish texture.

In all of the molds in accordance with the invention it is seen thatthere is a non-chilling or sand wall against which the molten metalcontacts, but there is a chill block at the bottom. Instead ofcongealing the molten metal from all sides simultaneously as in theprior art practices, there is here a relationship in which the settingup of the metal is started at the bottom chill block and it can progressup, with the formation of a uniform texture in the casting.

Desirably, where using a metal core, a metal having low oxidizability ispreferred, as for instance nickel chromium steels. A slight taper may begiven in instances desired, such as oneeighth inch per foot,particularly where relatively long molds are involved.

Bars and hollow shapes may thus be formed in quite wide variety ofdimensions, and of metals such as bronzes, copper-lead alloys, andantifriction alloys; and anti-friction castings initially formed as longhollow cylinders by use of cores can, where desired, be cut into aplurality of sections, axial and transverse, providing high uniformityof texture.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims, or the equivalent ofsuch, be employed.

I therefore particularly point out and distinctly claim as my invention:

1. Means for casting metal, comprising an axially sectioned metal shell,sand liner sections therein forming when assembled mold cavities and amold-filling well therebetween, a settling chamber at the bottom of thefilling well, a plurality of vertically spaced openings from saidfilling well to said mold cavities, said openings expanding outwardlyand downwardly to the mold cavities to a substantial extent, whereby jeteffects of metal flowing into said cavities are minimized, and at theirentrance to the mold cavities having their vertical dimensionapproximately onehalf that of the intervening wall between openings andbeing also from one-third to onefourth the diameter dimension of themold cavities, metal blocks at the ends of said mold cavities includingcore-centering means, and chill cores between said blocks.

2. Means for casting metal, comprising an axially sectioned shell, sandliner sections therein forming a mold cavity and a mold-filling wellalongside, a settling chamber at the bottom of the filling well, aplurality of vertically spaced openings from said filling well to saidmold cavity, said openings expanding outwardly and downwardly to themold cavity to a substantial extent, whereby jet effects of metalflowing into said cavity are minimized, and having their verticaldimension where entering the mold cavity approximately one-half that ofthe intervening wall dimension between openings and being one-third toone-fourth the diameter dimension of the mold cavity, metal blocks atthe ends of said mold cavity including core-centering means, and a chillcore between said blocks.

3. Means for casting metal, comprising an axially sectioned shell, sandliner sections therein forming a mold cavity and a mold-filling wellalongside, a settling chamber at the bottom of the filling well, aplurality of vertically spaced openings from said filling well to saidmold cavity, said openings expanding outwardly and downwardly to themold cavity to a substantial extent, whereby jet effects of metalflowing into said cavity are minimized, and having a vertical dimensioninto the mold cavity approximately onehalf that of the dimension of thewall space intervening between openings, and metal blocks at the ends ofsaid mold cavity including core-centering means.

4. Means for casting metal, comprising an axially sectioned metal shell,sand liner sections therein forming a mold cavity and a mold-fillingwell alongside, a settling chamber at the bottom of the filling well, aplurality of vertically spaced openings from said filling well to saidmold cavity, said openings expanding outwardly and downwardly to themold cavity to a substantial extent, whereby jet effects of metalflowing into said cavity are minimized, metal blocks at the ends of saidmold cavity including core-centering means, and a chill core betweensaid blocks.

5. Means for casting metal, comprising an axially sectioned shell, sandliner sections therein forming a mold cavity and a mold-filling wellalongside, a settling chamber at the bottom of the filling well, aplurality of vertically spaced openings from said filling Well to saidmold cavity, said openings expanding outwardly and downwardly to themold cavity to a substantial extent, whereby jet effects of metalflowing into said cavity are minimized, and metal blocks at the ends ofsaid mold cavity including core-centering means.

6. Means for casting metal, comprising axially divided sectionsincluding shell sections and baked sand sections therein forming a moldcavity, hinge means for holding the sections, a taper core,core-centering means including a metal chill block in the bottom of themold, and a plunger for moving said core through said block.

7, Means for casting metal, comprising axially metal chill block in thebottom of the mold hav- 7 ing the same outer perimeter as that of themolten metal positioning against it in the mold cavity, and vent-waysbetween the sand sections and, shell.

9. Means for casting metal, comprising axially divided sections forminga mold cavity and a mold-filling well alongside, a settling chamber atthe bottom of the filling well, and a plurality of vertically spacedopenings from said filling well to said mold cavity, said openingsexpanding outwardly and downwardly to the mold cavity to a substantialextent, whereby jet effects of metal flowing into said cavity areminimized.

10. A process of casting, comprising flowing the fluid metal through avertically extending filling zone, settling out solid particles therein,passing the fluid metal thence laterally through expansion openings inprogressively higher succession into a solidifying cavity to contactwith sand side Walls and central and end metal chill walls.

11. Means for casting metal comprising axially divided sections, a moldcavity and a mold-filling well alongside, and a plurality of verticallyspaced openings from said filling well to said mold cavity, thetransverse and vertical dimensions of said openings being greater at themold cavity than at the filling well, whereby jet effects of metalflowing into said cavity are minimized.

SAMUEL ROSS MCBRIDE.

